1. Field of the Invention
This invention relates to an electronic component built-in multi-layer wiring board having an electronic component built in thereto, and a method of manufacturing the same.
2. Description of the Prior Art
With the recent miniaturization of electronic equipment or the like, the multi-layer wiring board, which is one of the parts of the electronic equipment or the like, has required various improvements, and the chip size of the wafer level package (WLP), for example, that is surface mounted on the multi-layer wiring board has been reduced with respect to the number of IC pins.
Thus, a problem often arises where the bump pitch of a usual WLP is too small to allow for surface mounting of the WLP on the multi-layer wiring board. To respond to this problem, mixing of wiring patterns or electrodes having different wiring pitches on the multi-layer wiring board will reduce the whole production yield. With respect to this problem, for example, a solution as the multi-layer wiring board disclosed in JPH 11-317582 is proposed.
Specifically, the multi-layer wiring board in JPH 11-317582 has a structure in which the mother wiring board having a usual-density wiring pattern formed thereon has a recess formed therein, the recess contains a carrier wiring board having a high-density wiring pattern formed thereon, and the wirings are electrically connected. The multi-layer wiring board may thus surface mount various electronic components of different electrode pitches.